Research Reports - Can baroreflex sensitivity and heart rate variability predict late neurological outcome in patients with traumatic brain injury?
J Neurosurg Anesthesiol. 2014 Jan;26(1):50-9
Hendén PL, Söndergaard S, Rydenhag B, Reinsfelt B, Ricksten SE, Aneman A.
BACKGROUND: Previous studies have suggested that depressed heart rate variability
(HRV) and baroreflex sensitivity (BRS) are associated with early mortality and
morbidity in patients with acute brain injuries of various etiologies. The aim of
the present study was to assess changes in HRV and BRS in isolated traumatic
brain injury (TBI), with the hypothesis that measurement of autonomic nervous
system dysfunction can provide prognostic information on late neurological
MATERIALS AND METHODS: Nineteen patients with TBI, requiring mechanical
ventilation, sedation and analgesia, and with arterial and intracranial pressure
monitoring for at least 1 week, were included. Physiological and treatment
variables were collected and power spectral analyses of HRV and BRS analyses in
time domain were performed daily. HRV in the high-frequency (HF) and
low-frequency (LF) domains, as well as LF/HF ratio and total power, were
investigated. The power of these variables to predict poor (Glasgow Outcome Scale
Extended [GOSE] score <5), late (1 y) neurological outcome was assessed.
RESULTS: Total power, LF, HF, and BRS were all significantly depressed in
patients with GOSE score <5. This difference could not be explained by a more
severe brain injury at admission or more extensive use of sedative or analgesic
drugs. The autonomic variables predicted the late neurological outcome with areas
under the receiver-operating curves between 0.78 and 0.83 (sensitivity: 0.63 to
0.88 and specificity: 0.73 to 0.82).
CONCLUSIONS: HRV and BRS measures in TBI patients during intensive care
treatment, including sedative, analgesic, and vasoactive drugs, may identify
patients with poor late neurological outcome.